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High Angle Conveying, the Vital (missing) Link to IPCC Systems – 2017

Belt Conveyor Technology

High Angle Conveying, the Vital (missing) Link to IPCC Systems – 2017

Installations and recent studies have demonstrated the technical and economical advantages of high angle conveying for optimization of any IPCC system, yet that industry continues to struggle with the use of conventional solutions to achieve the high angle function.

By:

Joseph A. Dos Santos

(ed. WoMaMarcel - 07/4/2017)

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The Dos Santos sandwich belt development began timidly, extrapolating the Loop Belt into a double-loop S-shape. Fig. 8 shows the concept. By introducing a point of curvature reversal along the profile, above that point the approaching outer belt can become the idler supported inner belt while the approaching inner belt can become the outer belt, imparting the radial hugging load that develops the bulk material’s internal friction, to facilitate high angle conveying.

Fig. 8: S-Shape Sandwich conveyor schematic.

Extrapolating the Loop Belt principle further, introducing a multitude of curvature reversals along the profile produced the Snake Sandwich High Angle Conveyor, illustrated in Fig. 9 as it was first disclosed and submitted to the USA Patent Office in 1980. Fig. 10 shows the realization of the Snake Conveyor, years later, by Dos Santos International.

Fig. 9: Snake Sandwich conveyor schematic.

Fig. 10: DSI Snake Sandwich high angle conveyor.

The USA Bureau of Mines (BOM) Study determined that the Snake Sandwich High Angle conveyor was the best solution for the high tonnage requirements of the open pit mining applications. It thus recommended that the system be developed to commercialization.

Other variations of sandwich belt high angle conveyors were developed by the writer during the BOM Study. These too were pursuant to the guiding principle of the development – “The prophecy”.

The Mechanically Pressed Sandwich conveyor, depicted in Fig. 11, as first disclosed, utilizes equalized pressing rolls on the top belt to apply a hugging pressure onto the conveyed bulk material. Unlike the naturally conforming radial pressure of the Snake conveyor, the mechanically pressed system requires very close attention to equalization and spacing of the pressing rolls, in order to ensure a uniform pressure onto to the bulk material, without lapse. Fig. 12 shows the realization of the Mechanically Pressed Sandwich conveyor, years later, in the Continental HAC.

Fig. 11: Mechanically pressed sandwich conveyor schematic.

Fig. 12: Continental HAC.

From the extensive work of the BOM study, J.A. Dos Santos wrote and published the landmark article “Evolution of Sandwich Belt High Angle Conveyors” [2]. That writing, now 36 years old, articulated the complete theory of sandwich belt high angle conveyors, rationalized in the conventional conveyor technology. It established the standards of design that continue to this date.